How many unpaired electrons are present in Ni²⁺ cation (atomic number = 28)

1. 0

2. 2

3. 4

4. 6

The correct order of increasing energy of atomic orbital is: 

1. 3s, 3p, 4s, 3d, 4p

2. 3s, 3p, 3d, 4s, 4p

3. 3s, 3p, 4s, 4p, 3d

4. 3s, 3p, 3d, 4p, 4s

Elements upto atomic number 103 have been synthesized and studied. If a newly discovered element is found to have an atomic number 106, its electronic configuration will be:

1. [Rn] 5f¹⁴, 6d⁴, 7s²

2. [Rn] 5f¹⁴, 6d¹, 7s² 7p³

3. [Rn] 5f¹⁴, 6d, 7s⁰

4. [Rn] 5f¹⁴, 6d⁵, 7s¹

What is the correct family and electronic configuration for element Z = 114?

1. Halogen family, [Rn]5f¹⁴6d¹⁰7s²7p⁵

2. Carbon family, [Rn]5f¹⁴6d¹⁰7s²7p²

3. Oxygen family, [Rn]5f¹⁴6d¹⁰7s²7p⁴

4. Nitrogen family, [Rn]5f¹⁴6d¹⁰7s²7p⁶

The electronic configurations of Eu (Atomic no. 63), Gd (Atomic no. 64) and Tb (Tb Atomic no. 65) are

1. [Xe]4f⁶5d¹6s², [Xe]4f⁷5d¹6s² and [Xe]4f⁹6s²

2. [Xe]4f⁶5d¹6s², [Xe]4f⁷5d¹6s² and [Xe]4f⁸5d¹6s²

3. [Xe]4f⁷6s², [Xe]4f⁷5d¹6s² and [Xe]4f⁹6s²

4. [Xe]4f⁷6s², [Xe]4f⁸6s² and [Xe]4f⁸5d¹6s² 

The magnetic moment of 2.84 BM can be shown by:  

(At. no. Ni = 28, Ti = 22, Cr = 24, Co = 27)

1. Ni²⁺

2. Ti³⁺

3. Cr³⁺

4. Co²⁺

Which is the correct order of increasing energy of the listed orbitals in the atom of

titanium?

1. 3s 4s 3p 3d                   

2. 4s 3s 3p 3d

3. 3s 3p 3d 4s                   

4. 3s 3p 4s 3d

If the principal quantum number n=6, the correct sequence of filling of electrons will be:

Which one of the following ions has electronic configuration [Ar]3d⁶?

(At. no: Mn = 25, Fe = 26, Co = 27, Ni =28)

1. Ni³⁺               

2. Mn³⁺

3. Fe³⁺               

4. Co³⁺

Which one of the elements with the following outer orbital configurations may exhibit the

largest number of oxidation states ?

1. 3d³, 4s²

2. 3d⁵, 4s¹

3. 3d⁵, 4s²

4. 3d², 4s²